Image forming apparatuses are apparatuses that form an image on print media, e.g., sheets of paper, according to an input image signal. Examples of image forming apparatuses may include a printer, a copier, a fax machine and so-called a multi-functional peripheral products that combine some of the functionalities of the afore-mentioned.
In order to accomplish the formation of images on print media, an image forming apparatus includes a number of sub units and components accommodated in its main body that defines the overall external appearance of the image forming apparatus. Such sub units and components may generally include, for example, a print media storage unit for storing print media, a pickup unit for picking up the print media from the print media storage unit typically one medium at a time, a feeding unit for feeding the picked up print media further along the media delivery path, a developing unit for forming a. visible image using developer, e.g., toner, on the print medium, a fusing unit for fusing or fixing the developer image on the print medium and an exit unit for discharging the print medium having the developer image thereon to the outside of the main body.
Some of the above units and components may include one or more rotary members. For example, the developing unit may include a number of rotary members, the rotational operation of each of which is involved in the formation of the developer image on the print media. These rotary members of a developing unit may include, for example, a photoconductor provided with a photosensitive surface, on which an electrostatic latent image is formed by a light exposure, a charging roller for charging the photoconductor, a developing body for supplying the developer to the photoconductor to develop the electrostatic latent image formed thereon into a visible image and a supply roller for supplying the developer to the developing body.
Such developing unit may also include additional rotary members, which may include, for example, a scatter prevention member, which arranged to oppose and to be spaced apart from the photoconductor, and which operates to produce an air current for counteracting the air current resulting from the rotation of the photoconductor so as to prevent the developer scattered from the photoconductor from contaminating the print media.
The scatter prevention member may be rotated at a high speed by the rotary force transmitted from the photoconductor through a power transmission device that includes a gear or a train of gears. When the scatter prevention member is rotated at such a high speed to generate the air current, the scatter prevention member can generate or experience vibration. Such vibration may be transmitted to the photoconductor through the power transmission device, and may adversely impact the image quality, for example, horizontal stripes may develop in the resulting image.